Questions tagged [hydrangea]

Genus of flowering plants, also known as Hortensia.

Also known as Hortensia, Hydrangea is a genus of flowering plants, of family Hydrangeaceae. There are about 70 species in the genus, and they are native to South and East Asia, plus North and South American. They can be deciduous or evergreen, although the cultivated temperate species are generally deciduous.

Most Hydrangea species have white flowers, although some (notably H.macrophylla which is also the most common in cultivation) can be blue or pink according to the pH of the soil (colors as per litmus paper). This effect is due to "hyper-accumulating" of the acidity in the petals by the plant.

Hydrangea are generally grown as ornamental plants due to their large flowerheads. Hydrangea are moderately toxic, although the Japanese ama-cha tea is made from Hydrangea leaves.

Use this tag for all questions about Hydrangea plants

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Should I remove the dead flower heads from my hydrangea?

Earlier this year, I bought a hydrangea (from Ikea of all places!) and planted it out in the garden. It flowered nicely for a while, but the flowers have pretty much finished now and nearly all of the original leaves have withered. New leaves are…
Mal Ross
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How do I change the color of my hydrangea flowers?

So, I've heard that people sometimes mix a bit of lemon juice in when they water blue hydrangeas, they say it keeps them blue if the soil is lacking in acid. I was wondering, I have a pink indoor hydrangea plant; would it be possible to alter the…
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How do I prune my mop-head hydrangea?

I have a five year old Annabelle Hydrangea that is getting bushy. I have lightly pruned it in the past, but I don't know really know how I am supposed to do it. It is about 4' high and 6' wide. How do I prune it to optimize the flowering?
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Why isn't my hydrangea producing flowers?

My hydrangea is very leafy, but not producing flowers. Should I be adding something to the soil? This is the second consecutive year and I am totally perplexed. Appreciate any and all assistance. Thank you.
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What Should I look (out) for when purchasing a hydrangea plant?

I was about to buy a potted hydrangea as a last minute gift. I looked at the stem and it appeared dry, brittle and brown at the base of the plant. It's nice and green and firm near the heads of the flowers. Here is a picture that attempts to capture…
Yann
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Can flowers change colour after forming?

I'm actually studying for a chemistry exam, and in the Wikipedia page for Hydrangeas, it states that In these species the color (flower) is affected by soil pH. So the plant evidently takes the nutrients from the soil, and depending on the pH the…
QCD_IS_GOOD
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How should I deadhead a Hydrangea?

How do I remove the dead flowers on my Hydrangea? Do I just cut them off at the bottom of the dead flower bloom? Please advise what and how I should handle the hydrangea flowers after they turn brown.
Betty Cefalu
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What is wrong with my Hydrangeas

My hydrangeas were looking beautiful until a couple weeks ago. Then I started noticing that some of their leaves had these gray powdery looing spots on them, their blooms started having brown spots and their new leaves have some yellow ones. I…
Claire
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Why does my Mathilda hydrangea have an old green flower and a new purple one on the same stem?

Hydrangeas are my favorite flowers. I only have one potted Mathilda gutges plant in my condo. I don't know much about their care. The plant had three flowers. It was dying and I cut two of them because they looked really bad. One survived and it's…
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Cuttings growing leaves underground

I took a cutting from my hydrangea. I left two sets of leaves and plucked off the rest. I then stuck the plant into a blend of soil and perlite with two nodes under the soil. It has sprouted a few new leaves so I decided to transplant it, but when I…
jkd
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How do I treat a Hydrangea?

We have three hydrangea bushes. We didn't trim the dead sticks on them because of so many stories being told to us saying yes, trim them back because it will help them bloom more; and no because the dead ones are what makes them bloom. I'm also told…
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Should I cut off hydrangeas' early blooms?

I have some hydrangeas which I keep in the greenhouse because of the very cold winters we get. They have started to bloom but I don't know if thats bad because what I want is more blooms during summer. In order to achieve that should I cut off their…
Claire
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Why did my hydrangea's flowers die?

I bought these hydrangeas yesterday, today the red one's flowers died and the white one"s don't look as good as yesterday either. I haven't watered or repoted them yet. Update: 4 hours after I watered them. Thank you for the advices! The red one…
Claire
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Dying Hydrangea

I have had this hydrangea for a couple of weeks. When I first got it, it had beautiful, big blue blooms. But, now it seems to be dying. I'm keeping it in a place where it is shaded for most of the day, except the morning. What should I do? Thank…
Claire
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Hydrangea's allelopathic effects on crops?

I was wondering if hydrangea had any effects on the growth of other plants. Doing a google search only told me that hydrangeas are immune to juglone. However I'm more interested in the effects of hydrangea on other plants, will growing hydrangea…
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